As a result of our collaborative work with the University of California at San Diego, we have begun to model the oxygen delivery system in exercising muscle. We have already solved a system of oxygen diffusion combined with hemoglobin binding kinetics in the capillaries for one and two dimensions. We are now testing this nondimensionalized approach against known solutions. We plan to expand our model to include an intermediate layer of oxygen diffusion combined with myoglobin binding kinetics in the muscle cytosol. We believe that this model will help us understand the interesting results we have obtained in the quadriceps exercise study and may even be used to predict other physiologically important processes, including the role of nitroxide binding in intense exercise. This model may also be generalized to examine other important conditions which comprmise oxygen delivery such as stroke or peripheral vascular disease.